Liquid fuel supply device for use with internal-combustion prime movers



Aug. 20, 1946. v R, J [F ELD 2,406,296

LIQUID FUEL SUPPLY DEVICE FOR USE WITH INTERNAL- V COMBUSTION PRIME MOVERS Filed Aug. 21, .1945

mvezvtoz r" I 1 1 I Q Patented Aug. 20, 1946 LIQUID FUEL- SUPPLY DEVICE FOR USE WITH 1 INTERNALJJOMBUSTION PRIME MOVERS Richard Joseph Ifield, Birmingham, England, as-- signor to Joseph Lucas Limited, Birmingham,

England Application August-21, 1945, Serial No.'611,754

In Great Britain July7, 1944.

Claims.

This invention has, for its object to provide an improved liquid fuel supply device for use with an internal combustion prime moverof the kind having a fuel supply system which is fed by a pump, the latter derivingits motion from the prime mover. supply an adequate initial charge to the system when starting the prime mover, the rate of actuation of the pump. at that period being normally inadequate and a supplementary supply device being, in consequence necessary.

In the accompanying sheet of explanatory drawings:

Figure 1 is a diagrammatic sectional side View of a liquid fuel supply device constructed in accordancewith the invention.

Figure 2 is a fragmentary sectional view showing the control valve inv a'difierent position.

Figure 3 is a view similar to Figure 1 illustrating a modified form of the invention.

In carrying theinvention into eilect as shown in Figures 1 and 2, I employ a hollow cylindrical body a'having a pair of coaxial parts b, c of different internal diameters, and provided in its interior with an axially arranged hollowstem d.v

In the outer end of the body part b, whichis of smaller internal diameter than the .body part c, are formed three passages e, 1, g whichat their outer endsterminate in connections h, z, y'for pipes (not shown) leading respectively to the supply pump, the primemover, and ya sump. The inner ends of the passages e, 1, y and theadjacent end of the hollow stem d are terminated by a transverse bore 70 in the body part b, and in this bore is arranged a rotary valve. m adapted to effect the controls hereinafter described. Also the inlet passage'e, that is, the passage, communireating with the pump connection h, is provided with a branch passagen leading to. the. adjacent end of the interior of thebody part b. Likewise the passage 9, that is, the passage ,communicat.- ing with the sumpconnectionj is provided with a branch passage 0, this being arranged incommunication with the adjacent end of the interior,

of the body part c, and beingprovided witha non-return valve 10.

Within the I body a is slidably arranged a stepped piston q consisting of two parts ofv different diameters situated respectivelyv in the. body parts b, c. The pistonq isprovided with packing rings 1 of U- or equivalent cross-section, and is loaded by a spring s arranged to. move the piston towards the end of the body a containing the valve m.

The mode of action is as follows:

The purpose of the device is to- Assuming the larger capacity bodypart -c to have previously been filled with liquid fuel, and the valve m to be in the position shown in Figure 1 in which it connects the hollow stem d with the delivery passage 1 leading to the prime mover connection i, the setting of the pump in motion by actuation of thestarting motor of the prime mover, causes fuel to be supplied by the pump to the. adjacent end of the smaller capacity body "part b. The rate of this supply may be slow, but its effect on the piston q is to move the latter against the action of its loading springs 'in the direction for displacing the content of thelarger capacity body part c alonggthe hollow stem 01 and through a transverse passage t in the valve on to the connection i leading to the prime mover, openings u in the endof the stem remote from the valve providing .the required communication between the body part c and the stem. This displacement is made in suflicientvolume nd at a sufficient rate to ensure the required adequate initial supply of liquid fuelfto the prime mover until the pump can'establish the. normal direct supply. Meanwhile the piston lq slides along the stem 02 under thepressure of the liquid supplied by the pump, and when it approaches the end .of

' its movement the small end of the piston uncovers will) ports 1; in the stem which allow fluid to flow from the pump into the stem and thence through the valve 112 to the prime. mover. At the same time fuel can enter. the enlarging space between the larger ,end of the piston q and the inner end of the body part c from the passage g leading to the sump.. In this phase the valve m prevents direct intercommunication between the pump and sump passages e, 9. When it is required to stop the prime mover the valve m is turned to the position shown in-Figure 2 in which it cuts oil the connection with the delivery passage 1 and interconnects the pump and sump passages e, g and the stem 01. The piston q now returns to its initial position. under the action of .the spring 5, and while so doing liquid flows from the pump into the larger capacity bodypart c throughvthe stem d, therebyproviding the volume of liquid fuel to be used in the next starting operation .of.the prime mover. fuel previously drawn into the body part 0 past the non-return valve p is displaced past the larger piston packing ring r. 1

In addition. to thepassages above described, I preferably also. provide a balancing passage :1: in the smaller end of ,the piston q,.this balancing passage being arrangedtoico-operate with the ports 12 in the stem'd for putting the latter into Duringthe. return of. the piston q the part when the piston approaches the end'of 3 communication with the inner end of the body its movement under the action of the liquid supplied by the pump, thus balancing the fluid pressures on the two sides of the large end of the t 1 piston, Further I may provide in the periphery of the valve m a groove yfor establishingcommunication between the delivery passage 1 and :r, I the atmosphere or a drain when the supply of fuel to the prime mover is cut ofil.)

For enabling the valve m to eifect the controls T above described, the ends of the transverse passage t in the valve are enlarged as shown.

/ In the modified construction shown in' Figure 3 l I employ a body 2 which i provided with inlet and delivery connections h i for pipes (not v shown) leading respectively to the delivery-side;

of the supply pump'and the prime mover: '-At a position adjacent to the outlet connection i the body 2 is bored to form a stepped cylinder a and in this cylinder is slidably arranged a stepped piston a the latter being loaded by a spring 5 Parallel with the bore -of the cylinder a there are formed in the body 2 three other and-smaller 1 bores 3,14, 5, and in these three bores are respectively arranged three lidable plunger-like valves V The first bore 3 communicates with the outlet connection i and is connected by passages 9,1 Ill to the larger end of the cylinder a and the second bore 4. Communication between-the outlet connection 2' and the passages 9, NJ is con- 1 trolled by the valve 6 (herein termed the control 1 valve) which is slidable in the bore 3." The control 1 valve Bis operable by an external lever H through 1 a pinion l2 and a rack' I 3, or by any other suitable means.

At oneend the second bore, 4 communicates witha passage [4 leading to the smaller end of the cylinder a and at or near its other end this borelis formed with an enlargement 4 The valve: 1 (herein' referred to'as the automatic valve)-in the bore 4 is loaded by a spring Hi situated in the bore enlargement 4 and acting on a head'l on the adjacent end of the valve The-other end of. the automatic valve 1 is of conical or other form, and cooperates with an annular seating or shoulder IS in the bore 4 for controlling communication between the passages The third'bore 5-communicates with the inlet connection ch and is connected at one end to second bore 4 and the associated passage I4 by another passage IT. The adjacent end of the valve 8 ,(herein termed the throttle valve) in the bore 5 i of conical or other form, and co-V operates with an annular seating or shoulder It in this bore for regulating the rate of flow of liquid fuel from the inlet connection 71. to the" passage ll. The throttle valve-8 is operable by an external lever l9ithrough a pinion 20 and a rack 2!, or by any other suitable means. r

' To-permit a restricted quantity of liquid fuel toflowfrom the passage I! to the passage It, and thenceto the outlet connection i when the prime mover is being started, a by-pass passage formed at or near its closed end with ports 21 through which liquid can flow from the passage H to the chamber 26 when the by-pass valve is posed to the fuel pressure inthe passage l1.

When this pressurerises to a predetermined amount the automatic valve I opens and establishes 'free communication between the passages l1; Ill."

The enlargement 4 of the bore 4 containing I the automatic valve 1 communicates with a connection 30 for a pipe (not shown) leading to the suction side of the supply pump. Also the'bore enlargement 4 is connected by a passage3 I to a space'l32 in the body'2 containing the rack 2| 7 and pinion 26] associated with the throttle valve 8 ,Moreover, the bore enlargement 4 is connected by another passage33 to one end of the bore3 containing the control valve 6, the other end of this bore (which contains the rack l3 asso-' vciated with the control valve) being in communication with a vent or drain opening 34. Further,

the throttle valve 8 is formed with an axial bore V 35 for permitting access of fuel from the'passage H to the remote end of the throttle valve,

vso that the ends of this valve are subject to balanced fuel pressures. 1 7

Assuming that the throttle valve 8 is open, the'larger-end of the cylinder a is filled with liquidfuel, and the control valve 6 is in its open position as shown in which the larger end of the cylinder communicates with the-outlet connection i the setting of the pump in motion causes liquid. fuel in the passage I! being insufficient to v openv the automatic valve 1, or to overcome the spring .9 As the pump accelerates the difference m in the fluid pressures acting 'on opposite sides of 24 is provided? between the passages 11, Ill, this by-pass passage bein'g controlled .by a valve 25 r responsive to the liquid pressure in the'passagei H. The by-pass valve 25' mayiconsist' as shown of a spring-loaded hollow piston which'is slidablein a chamber 26 connecting the bypass passage 24 to the passage l1, and which has a closed end exposed to the interior of the last mentioned" passage, the peripheral wall of the piston being fuel to besupplied by the pump to the prime mover through the by-pass' valve 25 and the delivery connection i the initial pressure of the the by-pass valve 25 increases until it reaches a value which causes ,the'by-pass'valve to close quicklyiagainst the action of its loading spring 29. The consequential rise of pressure in the passage I'Lby acting on the smaller end of the piston q moves the latter against the action of its loading spring 8 and discharges liquid fuel from the larger end of the cylinder through the delivery connection 2' Further rise of pressure in the passage l'l opens the automatic valve 1, enabling the full supply of liquid fuel required by the prime mover to fiow from the passage l1 pastethe automatic valve to the delivery connection 2' This enables the piston 61 to return to its initial position, and the larger end of the cylinder a to be refilledthrough the passage 9 with the volume of liquid fuel to be used in the next starting operation of the prime mover. The cylinder a is providediat the junction of its larger and smaller partjs rwith a venting passage 36 to prevent entrapped air orleakage fluid from interfering with the proper action of the piston q To stop the prime mover the control valve 6 is moved to its close'drposition in which it interrupts commuhi .v cation between the delivery connection i and the passages 9, |ll, and establishes communication For enabling a small quantity of liquid fuel,

suflicient for slow running of the prime mover, to flow from the inlet connection h to the passage ll independently of the throttle valve 8, any convenient by-pass passage 3'! is provided in the body 2, this passage being controlled by a manually adjustable needle valve 38.

By this invention I am able to effect the required initial supply of fuel to the prime mover in a very satisfactory manner. The invention is not, however, restricted to the examples described as subordinate details may be modified to suit different requirements.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. For usewith an internal combustion prime mover of the kind specified, a liquid fuel supply device comprising in combination a body formed with a cylindrical bore of two different diameters, and with liquid fuel inlet and delivery openings, liquid fuel passages for connecting the smaller part of the bore to the inlet opening and the larger part of the bore to the delivery opening, a stepped and spring loaded piston slidable in the bore under the action of liquid fuel supplied under pressure to the smaller part of the bore from the inlet opening, a control valve movable to different positions for establishing and interrupting communication between the delivery opening and 6 the passage connected to the larger part of the bore, and means for establishing communication between the said passages under the control of the fuel pressure acting on the piston.

2 A liquid fuel supply device as and for the purpose claimed in claim 1, in which the fuel passage connecting the larger part of the cylindrical bore in the body to the delivery opening is formed in part by a hollow stem on which the piston is slidable, the stem being formed with ports whereby the smaller part of the said bore is connectible with the interior of the stem under the control of the piston.

3. A liquid fuel supply device as and for the purpose claimed in claim 1, in which the fuel passage connecting the larger part of the cylindrical bore in the bodyto the delivery opening is formed in part by a hollow stem on which the piston is slidable, the stem being formed with ports whereby the smaller part of the said bore is connectible with the interior of the stem under the control of the piston, and the control valve being of rotary form and arranged between one end of the hollow stem and the inlet and delivery openings.

4. A liquid fuel supply device as and for the purpose claimed in claim 1, in which the means for establishing communication between the liquid fuel passages includes a second valve responsive to the fuel pressure acting on the piston.

5. A liquid fuel supply device as and for the purpose claimed in claim 1, in which the means for establishing communication between the liquid fuel passages comprises in combination a second valve responsive to the fuel pressure acting on the piston, and'a spring loaded by-pass valve responsive to fuel pressure for providing a restricted communication between the passages when the second valve is closed.

RICHARD JOSEPH IFIELD. 

